exabyte dump parameters summary

From: Greg Gilley (gilley@ndl.com)
Date: Fri Apr 17 1992 - 17:51:13 CDT

Here are the results from my query about dump parameters for an Exabyte 8200.
It is interesting the wide variety of responses (apparently the driver uses
some unknown linear combination of the parameters). I called Exabyte and
they recommended for a 112M tape: 80 54000 6000 and said to use a ratio of
the lengths for the 15M, 54M, etc. They also said that SUNOS has a limit
of 2^31 bytes which is about 2.1G and not 2.3G for a single I/O stream.
Many thanks to all who replied.


  Greg Gilley
  gilley@ndl.COM [Numerical Design Limited]
  919-929-2917 (voice)
From: Tom Conroy <trc@NSD.3Com.COM>

Hi Greg:

The only parameter that will change will be 's' for size. This has
absolutely no effect on the data written to tape, only on the amount
of tape that dump estimates that it will use and when it thinks it
has run out of tape.

On a Sony P6-120MP (120M), I use 6000 for a size when matched with
the density and blocking in:

        /etc/dump 0udbsf 54000 100 6000 /dev/nrst1 /dev/sd0a

So I would use the following:

        Tape Length Size Parameter

        120 6000
        115 5750
        54 2700
        15 750

Remember, these are only estimates and come with no warranty whatsoever! :^)

Good Luck!

From: ebumfr@ebu.ericsson.se (Michael Rembis 6259)

This is what I use for my Sony P6-120M tapes:

/usr/etc/dump 0ubdsf 56 54000 6000 machine:/dev/nrst9 /dev/xy0h

Chao !

From: Eckhard.Rueggeberg@ts.go.dlr.de

We do it with the following script (for 90min tapes) :

if [ $# != 2 ]; then
        echo ""
        echo " Usage : dump_on_exabyte machine_name exatapeserver_name "
        echo ""
        exit 1

if [ `ping $1 | grep -c alive` != 1 ]; then
        echo $1 lebt nicht !!
        exit 1

if [ `ping $1 | grep -c alive` != 1 ]; then
        echo $1 lebt nicht !!
        exit 1

rsh $1 df | grep dev | colrm 10 > $DUMPFILE
for i
in `cat $DUMPFILE`
echo ""
echo Dumping $i from $1 on $2
echo ""
rsh $1 /etc/dump 0ucbfs 126 nobody@$2:/dev/nrst9 20000 $i

From: kkinners@ios.bc.ca (Kerry Kinnersley)

For the 8200 and the 115M tape I use:
0ucbsdf 126 6000 54000 for level 0 dump.

I don't see why you would want to use the 15M and 54M tapes since they are
so cheap. Don't forget the exabyte summaries are in ftphost.uni-augsburg.de
under /pub, perhaps they are listed in there?

Good Luck!

From: era@niwot.scd.ucar.EDU (Ed Arnold)

I don't know what you mean by 15M, 54M, and 115M tapes. The usual
dump parms we use with an 8200 writing to a sony P6-120 cartridge are:

dump 0ubdsf 126 54000 6000 /dev/nrst0 /dev/sd2c

From: ept@eptsun1.ctd.ornl.gov (E P Tinnel)

Hi ...


        /etc/dump 0ufbsd /dev/nrst1 100 6000 54000 /dev/rsd0a

for 112m tapes

From: herman@galileo.csc.ti.com (Herman Schuurman)

Although I have never used dump on our 8200 (we use Networker for
backups), the documentation suggested the following parameters:

        b=50, s=6000, d=54000

I guess you could adapt the size parameter (6000 for a 112m tape), to
account for the smaller 15M and 54M tapes.

From: ctm@sleepy.boeing.com (chuck malmsten)

We have an bunch of exebyte 8mm drives. I don't know the model
number. Is an 8200 an 8mm drive.

anyway, we use 8mm P120 tapes which hold about 1.3 gigabytes. The only "strange" thing
we do to get dump to write lots of data to these tapes is to tell dump the
tape density is 54000 bytes per inch. We then specify the tape length
accordingly (e.g. 2000 feet for 1.3 gig).

From: oran@spg.amdahl.com (Oran Davis)


Dump uses the 9 track standard as the reference for tape length and capacity.
1600bpi 9 track is standard. The effective length that the dump must see is as though
it is writing to 9 track.

the size parameter you pass to dump(8):

------------------- 4.1.1 manual ----------------------------
     s size
          Specify the size of the volume being dumped to. When
          the specified size is reached, dump waits for you to
          change the volume. dump interprets the specified size
          as the length in feet for tapes, and cartridges and as
          the number of 1024 byte blocks for diskettes. The fol-
          lowing are defaults:

               tape 2300 feet
               cartridge 425 feet
               diskette 1422 blocks (Corresponds to a 1.44 Mb
                           diskette, with one cylinder reserved
                           for bad block information.)
------------------- 4.1.1 manual ----------------------------

G = 1024*1024 (yes! number of 1M chunks)
ts = 2.3*G or 5*G or less if you have short or partially filled tape.
bf = blocking factor. The calture says 124 is best, <64K.

size = ((512 * bf ) + 1920) * (ts - 2048) / (bf * 10667)

 103400.49 = (512*124+1920)*(2044*1024-2048)/124/10667

 dump 0fbs /dev/nrst0 124 103400 /dev/rsd0g

The variouse tape sizes (ts) and standards (on the NTSC transports we all use):
Minutes NTSC PAL
15 258M 368M
30 516M 753M
60 1.032G 1.484G
90 1.548G 2.226G
120 2.044G (PAL: don't use - too thin and will give errors quickly)

Good luck,

>- Oran

From: Vlastimil Malinek <vlastimil.malinek@mrc-apu.cam.ac.uk>


        After much conversation with sun and other colleagues we use the
following parameters on our switchable 8500 exabytes.

# 2 gig length
# 5 gig length
/usr/etc/dump ${level}bcdsuf 112 4100000 ${length}

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